Jeff, responsible for some of the biggest TV hits of recent years including Cilla and Appropriate Adult, compared it to the mysterious substance from the Superman stories, which rendered the hero helpless if he was exposed to it.

He said: “I did think it was like putting Kryptonite in Superman’s pocket. Was taking Peter out of Lancashire a bit like cutting Sansom’s hair, but I’m pleased to report it’s not at all.

“One thing about Peter is he is a perfectionist and not only did he want to do a Cockney accent, he wanted to do a south-east London one and he’s done it.”

Jeff, who will be honoured with a special award at this year’s TV Baftas, is currently working on a show inspired by the Shannon Matthews case.

The schoolgirl was nine when she disappeared from her home in Dewsbury Moor, West Yorkshire, in February 2008, sparking a massive police investigation.

But she was discovered 24 days later at the home of her stepfather’s uncle, Michael Donovan, less than a mile away, where she had been imprisoned as part of a plan he and Shannon’s mother hatched to claim a £50,000 reward.

Jeff Pope (Jonathan Short/Invision)

Jeff said: “That estate, the Moorside Estate, was written off as being full of feckless people, but they got together and organised a search and found Shannon alive. The euphoria was immense, but then slowly punctured when they realised what had happened and the show is about how that place recovered from that betrayal.”

He will accept his award at the event, formally known as the House of Fraser British Academy Television Awards, which is hosted by Graham Norton at the Theatre Royal Drury Lane, London, and broadcast on BBC1 on Sunday May 10.